============================= [ BUG: Invalid wait context ] syzkaller #0 Tainted: G L ----------------------------- swapper/3/0 is trying to lock: ffff888035a712d0 (&gpc->lock){....}-{3:3}, at: kvm_xen_set_evtchn_fast+0x253/0xe80 arch/x86/kvm/xen.c:1819 other info that might help us debug this: context-{2:2} 1 lock held by swapper/3/0: #0: ffff888035a71850 (&kvm->srcu){.?.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:187 [inline] #0: ffff888035a71850 (&kvm->srcu){.?.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:294 [inline] #0: ffff888035a71850 (&kvm->srcu){.?.+}-{0:0}, at: kvm_xen_set_evtchn_fast+0x245/0xe80 arch/x86/kvm/xen.c:1817 stack backtrace: CPU: 3 UID: 0 PID: 0 Comm: swapper/3 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 print_lock_invalid_wait_context kernel/locking/lockdep.c:4830 [inline] check_wait_context kernel/locking/lockdep.c:4902 [inline] __lock_acquire+0xfa4/0x2630 kernel/locking/lockdep.c:5187 lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x1b1/0x370 kernel/locking/lockdep.c:5825 __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:174 [inline] _raw_read_lock_irqsave+0x46/0x90 kernel/locking/spinlock.c:240 kvm_xen_set_evtchn_fast+0x253/0xe80 arch/x86/kvm/xen.c:1819 xen_timer_callback+0x1db/0x2a0 arch/x86/kvm/xen.c:140 __run_hrtimer kernel/time/hrtimer.c:1930 [inline] __hrtimer_run_queues+0x142/0xa00 kernel/time/hrtimer.c:1994 hrtimer_interrupt+0x3e5/0x940 kernel/time/hrtimer.c:2113 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] __sysvec_apic_timer_interrupt+0x10b/0x460 arch/x86/kernel/apic/apic.c:1067 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline] sysvec_apic_timer_interrupt+0x9e/0xc0 arch/x86/kernel/apic/apic.c:1061 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63 Code: d6 92 02 e9 c3 42 03 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d e3 00 21 00 fb f4 cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffc90000197df0 EFLAGS: 00000206 RAX: 00000000000c02bb RBX: ffff88801ee92500 RCX: ffffffff8b8a9095 RDX: 0000000000000000 RSI: ffffffff8df21135 RDI: ffffffff8c1c3800 RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed100d4e67b5 R10: ffff88806a733dab R11: 0000000000000000 R12: 0000000000000003 R13: ffffed1003dd24a0 R14: 0000000000000003 R15: ffffffff90d7ae50 arch_safe_halt arch/x86/include/asm/paravirt.h:62 [inline] default_idle+0x9/0x10 arch/x86/kernel/process.c:767 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:199 [inline] do_idle+0x464/0x590 kernel/sched/idle.c:352 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:451 start_secondary+0x21d/0x2d0 arch/x86/kernel/smpboot.c:312 common_startup_64+0x13e/0x148 ---------------- Code disassembly (best guess), 1 bytes skipped: 0: 92 xchg %eax,%edx 1: 02 e9 add %cl,%ch 3: c3 ret 4: 42 03 00 rex.X add (%rax),%eax 7: 0f 1f 00 nopl (%rax) a: 90 nop b: 90 nop c: 90 nop d: 90 nop e: 90 nop f: 90 nop 10: 90 nop 11: 90 nop 12: 90 nop 13: 90 nop 14: 90 nop 15: 90 nop 16: 90 nop 17: 90 nop 18: 90 nop 19: 90 nop 1a: f3 0f 1e fa endbr64 1e: eb 07 jmp 0x27 20: 0f 00 2d e3 00 21 00 verw 0x2100e3(%rip) # 0x21010a 27: fb sti 28: f4 hlt * 29: c3 ret <-- trapping instruction 2a: cc int3 2b: cc int3 2c: cc int3 2d: cc int3 2e: 66 2e 0f 1f 84 00 00 cs nopw 0x0(%rax,%rax,1) 35: 00 00 00 38: 66 90 xchg %ax,%ax 3a: 90 nop 3b: 90 nop 3c: 90 nop 3d: 90 nop 3e: 90 nop